Many homeowners are eager to undertake a patio project, but may be scared off if the entire patio needs to be raised from the surrounding ground. The building process is not that different from level patios, it will simply have the additional step of building a retaining wall. It is something that is within the capabilities of someone with average do-it-yourself skills and the physical strength to do backyard chores.
Build a retaining wall that will border the patio and provide an area in which you can add the fill material for your base. Mark the boundaries of your patio with stakes. With a string, line level and tape measure, accurately mark the stakes at the planned height of your finished wall. Determine how many courses, or rows, of bricks you will need to reach your finished height. Keep in mind that you are going to completely bury the first course to give the retaining wall extra stability. Excavate a 12 inch wide and 6 inch deep trench for your first course. Compact the ground in the trench firmly. Add 2 inches of finely crushed gravel and level the surface. Make a level string line to serve as a guide for the top of your first course.
Lay the landscaping fabric in the trench so that the bricks can lie on top of it and the material can run up behind the finished wall. (see graphic) Lay the bricks level and side by side on the material, following the string line. Continue with additional courses in the same manner. As you lay the courses, add gravel between the fabric and the back of the brick. This will prevent soil from washing through the cracks in the wall.
Make a base for your patio that will consist of 4 inches of finely crushed gravel and 1 inch of coarse paver sand. Add fill dirt within the retaining wall area up to a point that leaves room for the base depth plus the brick paver height. Use a rake to level the dirt surface and compact the ground firmly. I recommend renting a heavy duty plate compactor. Add the gravel and spread in to a depth of 4 inches. Start in one corner where two sides of the retaining wall meet and form a 90 degree angle. Lay both the 1" PVC pipes on the gravel base about 6 feet apart and parallel to one another. This sets the first area in which you will lay the sand and pavers.
Add sand in this area to approximately 1+" depth. Use one of the 2 inch x 4inch pieces of lumber to screed the sand and make it level. This is done by starting on one end, resting the piece of lumber on the PVC pipes, then pulling the board toward you in a manner that leaves the sand level with the tops of the pipes and undisturbed.
Lay your first paver by holding it above the sand about an inch, pushing it up against both retaining wall bricks with pressure, and then sliding it down the edges of the wall - keeping some pressure against the wall bricks while you lower the paver. Repeat this process with more pavers.
Work outward from the corner and use the previous paver as your guide when lowering the stones. Do not drag the bricks into place or disturb the leveled sand when placing the pavers. Use a rubber mallet to tap them in to place tightly. Continue this process one small area at a time, screeding the sand as you go with the pipes and piece of lumber, and laying the brick pavers until you have completed the entire area.
Make a pass over the pavers with the plate compactor. Spread a 1/8 inch layer of sand across the pavers and sweep back and forth so that it works into all the cracks. Make another pass or two over the surface with the plate compactor, adding and/or sweeping the sand around as needed. Clean up the area by sweeping any excess sand away and your raised patio is complete.